<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<link href="css/bootstrap.css" rel="stylesheet" />
	</head>
	<body>
		<div class="input-group input-group-lg">
			<span class="input-group-addon">@</span>
			<input type="text" class="form-control" placeholder="Username" />
		</div>
		<br />
		<div class="input-group input-group-sm">
			<input type="text" class="form-control" placeholder="请输入要搜索的内容" />
			<span class="input-group-addon">百度一下</span>
		</div>
		<div class="input-group">
			<input type="text" class="form-control" placeholder="请输入要搜索的内容" />
			<span class="input-group-btn"> <button class="btn btn-primary" type="button">百度一下</button> </span>
		</div>
	</body>
</html>
